Merge remote-tracking branch 'origin/stable-2.0'
[bpt/guile.git] / libguile / values.c
CommitLineData
c15defef 1/* Copyright (C) 2000, 2001, 2006, 2008, 2009, 2011, 2012 Free Software Foundation, Inc.
ce212434 2 *
73be1d9e 3 * This library is free software; you can redistribute it and/or
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4 * modify it under the terms of the GNU Lesser General Public License
5 * as published by the Free Software Foundation; either version 3 of
6 * the License, or (at your option) any later version.
ce212434 7 *
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8 * This library is distributed in the hope that it will be useful, but
9 * WITHOUT ANY WARRANTY; without even the implied warranty of
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10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * Lesser General Public License for more details.
ce212434 12 *
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13 * You should have received a copy of the GNU Lesser General Public
14 * License along with this library; if not, write to the Free Software
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15 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
16 * 02110-1301 USA
73be1d9e 17 */
ce212434 18
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19#ifdef HAVE_CONFIG_H
20# include <config.h>
21#endif
22
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23#include "libguile/_scm.h"
24#include "libguile/eval.h"
25#include "libguile/feature.h"
26#include "libguile/gc.h"
27#include "libguile/numbers.h"
28#include "libguile/ports.h"
29#include "libguile/root.h"
30#include "libguile/strings.h"
31#include "libguile/struct.h"
32#include "libguile/validate.h"
33
34#include "libguile/values.h"
35
752af227 36SCM scm_values_vtable;
ce212434 37
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38/* OBJ must be a values object containing exactly two values.
39 scm_i_extract_values_2 puts those two values into *p1 and *p2. */
40void
41scm_i_extract_values_2 (SCM obj, SCM *p1, SCM *p2)
42{
43 SCM values;
44
45 SCM_ASSERT_TYPE (SCM_VALUESP (obj), obj, SCM_ARG1,
46 "scm_i_extract_values_2", "values");
47 values = scm_struct_ref (obj, SCM_INUM0);
7017846b 48 if (scm_ilength (values) != 2)
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49 scm_wrong_type_arg_msg
50 ("scm_i_extract_values_2", SCM_ARG1, obj,
51 "a values object containing exactly two values");
52 *p1 = SCM_CAR (values);
53 *p2 = SCM_CADR (values);
54}
55
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56static SCM
57print_values (SCM obj, SCM pwps)
58{
59 SCM values = scm_struct_ref (obj, SCM_INUM0);
60 SCM port = SCM_PORT_WITH_PS_PORT (pwps);
61 scm_print_state *ps = SCM_PRINT_STATE (SCM_PORT_WITH_PS_PS (pwps));
62
0607ebbf 63 scm_puts_unlocked ("#<values ", port);
9d47027e 64 scm_iprin1 (values, port, ps);
0607ebbf 65 scm_puts_unlocked (">", port);
9d47027e 66
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67 return SCM_UNSPECIFIED;
68}
69
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70SCM
71scm_c_value_ref (SCM obj, size_t idx)
72{
73 if (SCM_LIKELY (SCM_VALUESP (obj)))
74 {
75 SCM values = scm_struct_ref (obj, SCM_INUM0);
76 size_t i = idx;
77 while (SCM_LIKELY (scm_is_pair (values)))
78 {
79 if (i == 0)
80 return SCM_CAR (values);
81 values = SCM_CDR (values);
82 i--;
83 }
84 }
85 else if (idx == 0)
86 return obj;
87
88 scm_error (scm_out_of_range_key,
89 "scm_c_value_ref",
90 "Too few values in ~S to access index ~S",
91 scm_list_2 (obj, scm_from_unsigned_integer (idx)),
92 scm_list_1 (scm_from_unsigned_integer (idx)));
93}
94
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95SCM_DEFINE (scm_values, "values", 0, 0, 1,
96 (SCM args),
97 "Delivers all of its arguments to its continuation. Except for\n"
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98 "continuations created by the @code{call-with-values} procedure,\n"
99 "all continuations take exactly one value. The effect of\n"
100 "passing no value or more than one value to continuations that\n"
101 "were not created by @code{call-with-values} is unspecified.")
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102#define FUNC_NAME s_scm_values
103{
c014a02e 104 long n;
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105 SCM result;
106
107 SCM_VALIDATE_LIST_COPYLEN (1, args, n);
108 if (n == 1)
109 result = SCM_CAR (args);
110 else
c15defef 111 result = scm_c_make_struct (scm_values_vtable, 0, 1, SCM_UNPACK (args));
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112
113 return result;
114}
115#undef FUNC_NAME
116
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117SCM
118scm_c_values (SCM *base, size_t nvalues)
119{
120 SCM ret, *walk;
121
122 if (nvalues == 1)
123 return *base;
124
125 for (ret = SCM_EOL, walk = base + nvalues - 1; walk >= base; walk--)
126 ret = scm_cons (*walk, ret);
127
128 return scm_values (ret);
129}
130
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131void
132scm_init_values (void)
133{
df9ca8d8 134 SCM print = scm_c_define_gsubr ("%print-values", 2, 0, 0, print_values);
ce212434 135
b7bff2ba 136 scm_values_vtable = scm_make_vtable (scm_from_locale_string ("pr"), print);
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137
138 scm_add_feature ("values");
139
ce212434 140#include "libguile/values.x"
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141}
142
143/*
144 Local Variables:
145 c-file-style: "gnu"
146 End:
147*/